Deepwater dredge



W ma G. B. MASSEY DEEPWATER DREDGE Filed June 30, 1948 a; INVENTOR.

GEORGE B. MASSEY ATTYS moi s Patented Jan. 31, 1950 s'rA'res lenteur oFFICE l2 Claims.

This invention relates to deep water dredging and particularly to dredges of the dragline type.

Its main objects are to provide a novel and improved form of apparatus that will best meet all of the problems of deep underwater excavation of blasted rock as well as other materials; to provide an improved adaptation of the dragline bucket principle of deep water dredging; to provide an improved dragline dredge mechanism which may be carried by and operated from a floating hull but which in its normal excavating operation will have no effect tending seriously to disturb the disposition of the hull or to shift the position of the hull with respect to the terrain in which it is operative; and to provide in such dredge improved means controllable from the hull for directing the operation of the bucket as regards the submarine area to be excavated.

A specific embodiment of this invention is schematically illustrated in the accompanying drawings, in which:

Figure 1 is a top plan of a dragline dredge constructed according to this invention, including a partly diagrammatic representation of the operating mechanism.

Fig. 2 is a side elevation of the same; and

Fig. 3 is a detail in side elevation of a modiiied form of the dragline hauling mechanism.

In the form shown, the dredge comprises in general a floating hull I which has a well II extending vertically through it at approximately its center of buoyancy and proportioned to receive a heavy anchor block I2 designed to be suspended from said hull and to be lowered to rest freely upon the bottom of the body of water on which the hull floats so as to cooperate with mechanism for operating a dragline excavating bucket I3 without causing displacing strains on the hull.

With a View to simplifying this disclosure, the f drawings are largely diagrammatic, with the omission of details of power plant, Winches, motors and other mechanism well understood in the art and only incidentally related to the subject matter to be claimed herein.

The hull I0 is also provided with a second well Id extending through its bottom from one end of the hull for a considerable distance inward from said end to provide clearance for hoisting mechanism for the bucket I3 in various positions. The length of this well is related to the length of cutting travel of the bucket.

A pair of trusses I5 extend along the sides of the well I4 and throughout the entire length of the hull and carry tracks I6 upon which ride the wheels of a traveling carriage Ii from which the bucket I3 is suspended by four cables la which pass over hoisting mechanism represented by the drums I9. After passing the drums I9, the cables I8 extend to counterweights 20, being guided by appropriately located sheaves I2 and 22. The counterweights are preferably hung outside of the hull from arms 23 carried by the carriage I1.

It will be understood that appropriate winch mechanism for severalli manipulating the cables I8 to control tilting and hoisting movements of the bucket I3 is mounted on the carriage II. Such mechanism is represented diagrammatically by the drums is and, as will be understood by persons familiar with this art, may be of such nature as to be controlled by an operator in an appropriate cab ad on the carriage I?. The carriage I? is mounted to travel on the rails I6 and may be propelled by winch mechanism represented diagrammatically by the drum 25 and cables 26 and 26.I.

A second carriage 2l is mounted on the rails I6 at the opposite end of the hull I0 and carries a counterweight 28 designed to counterbalance the weight of the carriage I'I including that of the bucket I3, its load and its counterweights 20. The carriage 2l is arranged to travel in counterbalancing relation to the travel of the carriage I1, to minimize disturbance of the hull during the hoisting and dumping operations of the bucket.

For example, in the design of the hull shown in the drawings where the normal center of buoyancy is nearer one end of the' truss than the other, there is less room for travel of the carriage 21 than that of the carriage I'I. Therefore, the weight of the carriage 2'! and its counterweight may be assumed to be twice that of the carriage I1 and its load and the carriages would be driven Y so that the distance of the carriage 21 from the center of buoyancy would be at all times one-half of the distance of the carriage I'I from the center of buoyancy.

A diagrammatic representation of this relationship is shown in Fig. 1 where the cable 26 is attached to the forward end of the carriage I1, passes around the sheave 29, then over the driving drum 25 and then around a sheave 29.I at tached to the front end of the carriage 2'I and then passes backto a fixed point 28.! on the truss. A second cable 26.! is attached to the rear end of the carriage II, passes around a sheave 39 at the after end of the truss, then forward around a sheave M attached to the carriage and then back to a xed point 30.2 on the hull. Thus movement of the carriage I'I in the operation of the bucket will always be associated with a counter-weighting movement of the carriage 12'! in the opposite direction.

The anchor IZ is a rectangular block of heavy material, such as concrete, with bores 3l extending vertically through it to reduce the effect of suction when it is lifted from the ground and is provided with prongs 32 on its bottom surface so that it will grip the surface on which it rests.

The anchor block I2 is hung from four cables 33 in block-and-tackle arrangement for suspending, raising and lowering it carries on its upper surface the dragline hauling mechanism for pulling a pair of cables 34 which are attached to opposite sides of the bucket I3. In practice the hoisting cables 33 may be attached to the four corners of the anchor block, while the sheaves from which these cables hang on the hull are preferably closer to the fore-and-aft center line of the hull to avoid capsizing of the hull in the event of breakage of one of such cables.

In the form indicated in Fig. 2, the dragline hauling mechanism comprises a pair of winch drums 35. to the water, but their gearing and their electric motor are enclosed in a watertight housing S from which water may be excluded by air under pressure supplied by an armored tube 31 which passes over a sheave 38 and leads to appropriate power mechanism in a deck house 39 on the hull iii. The motor is similarly connected with its generatcrin the deck house 32 by a conductor cable 5.0 which may pass over a sheave, which together with the sheave 38 is mounted to travel vertically in a tower structure i I as by a suspending cable G2 carrying a counterweight which lifts these sheaves as the anchor i2 is lifted. The sheave 38 is, of course, large enough to prevent injury to the tube 37. Such lifting arrangement is indicated by dotted lines in Fig. 2, from which it will beunderstood that the movement of the sheave .'53 need only be half that of the vertical movement of the anchor block I2.

In `Fig. 3, instead of having the el ctricaliy :i

driven winch mechanism enclosed in a housing mounted on the anchor block, the dragine hauling cables 3d of the bucket are led over sheaves lf3 on the anchor block i2, then to sheaves and then to winch mechanism in the deck vIn this arrangement, .the anchor block I2 would be of increased weight to compensate for the absence oi the weight of the winch mechanism and for the upward pull on the cable Se working against the weight of the block I2.

The horizontal disposition of the hull IS with respect to the anchor block is controlled by two pairs ofhawsers 46 and l1 leading respectively from points adjacent to the four corners of the anchor block I2 to four correspondingly related spaced points near the opposite ends of the hull where they enter hawseholes I8 and are connected to Winches, not shown, whereby these hawsers may be manipulated to adjust the position of the hull with respect to the anchor.

The trusses I extend forward beyond the bow of the hull and the tracks for the carriage extend to a bumper block 49, where it will be in a position to empty the bucket into a barge 50 appropriately moored across the front of the hull as indicated in the drawing.

vAn illustrative example giving suitable dimensions for a dredge of this kind follows:

In horizontal contour the hull may be rectan- The winch drums may be exposed 1 operates is 25 feet wide.

guiar, 350 feet long, 85 foot beam, 19 feet deep at the after end and 13 feet deep at the forward end.

At the center of buoyancy of the hull is a well feet by 60 feet. In this well is suspended a block of reinforced concrete 30 by 50 feet by 10 feet thick, weighing 750 tons. This block would be'poured in place in layers or lifts. Prongs about 2 feet long would project downward in rows near the sides and ends of the block. The block is supported by four blocks and tackles mounted on the length of the dredge and feet beyond the bow. In View of the great weight of the anchor, the blocks and tackles are as close to the fore-andaft center line of the hull at their upper ends as the lifting of the anchor will permit to avoid capsizing of the hull in the event of cable breakage.

Upon the anchor are two sets of 10-foot diameter grooved drag drums which, with a first set of gears, may be in the water. The rest 0f the gearing and the totally enclosed mill type, direct current motors are enclosed in two watertight rooms with an air pressure of pounds per square inch to exclude water from these housing rooms. The air is cooled before being delivered to the housing by flexible tube or tubes 31 provided with a take-up arrangement. The compressor would preferably work on a closed circulation system with delivery and return tubes but might operate with a single tube with a pressure controlled discharge valve on the housing.

The electric current would be brought down in water-proof cables with take-up arrangement in the tower lll. Six large Counterweighted sheaves carry the flexible air tubes and electric cables for two sets of winch mechanisms. One end of each such cable is attached to the hull and the other is attached on the anchor.

The drag drums are each grooved for a 2% ,i inch diameter, 6 by 37 plow steel wire rope about 250 feet long with suitable flight rollers and sheaves to insure proper winding on the drums. The pull would be 150,000 pounds on each rope or 300,000 pounds stalling pull on the bucket. The bucket is a 30 cubic yard dragline bucket with teeth on its cutting edge, two drag ropes and four hoist lines. The bottom of the bucket would be a grillage of beams leaving holes for passage of water. The rear end of the bucket would rise at 30 from the bottom and would be open.

The bucket weight and half of the live load of rock are counterweighted, resulting in a hoisting and lowering weight of 50,000 pounds. The bucket is 12 feet wide and the well in which it The anchor block of concrete weighing '750 tons produces friction resisting horizontal motion of roughly 12-5 tons.

The speeds of operation are:

Feet per minute Anchor hoist 10 Bucket drag Bucket hoist 200 Carriage travel 100 The motors operating the anchor Vhoist are preferably in synchronism. The same is true of the bucket hoist ropes, the drive of the two carriages and that of the two drag drums.

Power is supplied by two 1200 horsepower Diesel engines driving direct current generators with motors distributed as required.

Hoist anchor 500 Drag ropes 1000 I-Ioisting bucket 1000 Carriage drives 100 Air compressor etc 300 Or a total while operating of 1500 rlhe operation of the dredge will be apparent from the foregoing description. The bucket is lled by hauling on the draglines 34, then the bucket is tilted by manipulating the cables I8 to bring it to its load-carrying position shown by trusses which are 25 feet apart and run the full 75 dotted lines I3.I. The carriage I'I is moved forward or back with the bucket. As the bucket approaches the truss, the carriage is driven forward to the dumping position and the load is discharged by tilting the bucket.

To move the hull the anchor would be hoisted about 3 feet or more to provide clearance over obstructions on the bottom of the waterway.

The digging could be in a straight line or the bow of the hull could be swung about the anchor block, by manipulating the four mooring lines, y

represented in Figs. 2 and 3 by lines 46 and 4l, and hoisting and resetting the anchor block, to dig like an ordinary dragline machine in an arc of a circle.

The strains of pulling the bucket into blasted rock to fill the bucket are borne entirely by the bucket, the two drag ropes and the two dragline drums. None of the digging strain is transmitted to the hull which remains still and quiet while excavating.

The operator would be stationed on the carriage from which the bucket is suspended. He would be at a point where the bucket would emerge from the water and would look down into the barge as the load was dumped. He would know the exact position of the bucket when digging and hoisting. Depth finders on the carriage would reveal the height of the bank ahead of the bucket at all times.

The herein-described dragline dredge is particularly intended for operation in deep water for the excavation of blasted rock and has many distinct advantages over certain existing types of dredges. As compared with a dredge of the bucket ladder type of comparable actual capacity,

its advantages are as follows:

tirely by the bucket, the two drag ropes and a the two drag drums. None of the digging strain is transmitted to the hull which remains still and quiet while excavating.

J. Requires no spuds or other bracing connections between the hull and ground.

It will be understood that numerous details of the construction shown and described may be altered or omitted without departing from the spirit of the invention as dened by the following claims.

I claim:

1. A dredge comprising a hull, a dragline bucket, means for raising and lowering said bucket from said hull adjacent one end thereof, an anchor block, means for raising and lowering said anchor block from said hull at approximately its center of buoyancy, a dragline extending between said anchor block and said bucket, and means for hauling said dragline to pull said bucket toward said anchor block when said anchor block is resting on the river bottom beneath said hull.

2. A dredge comprising a hull, a dragline bucket, means for raising and lowering said bucket from said hull adjacent one end thereof, an anchor block, means for raising and lowering said anchor block from said hull, a dragline extending between said anchor block and said bucket, and means on said anchor block for hauling said dragline to operate said bucket when said anchor block is resting on the river bottom beneath said hull.

3. A dredge comprising a hull, a dragline bucket, means for raising and lowering said bucket from said hull adjacent one end thereof, an anchor block, means for raising and lowering said anchor block from said hull at approximately its center of buoyancy, a dragline extending horizontally from said bucket to said anchor block and vertically from said anchor block to said hull, and winch means on said hull for hauling said dragline.

4. A dredge comprising a hull, an ancho-r block, means for raising and lowering said anchor block from said hull, a carriage mounted to travel along said hull toward and away from one end thereof, a dragline bucket, means for raising and lowering said bucket from said carriage, a dragline extending from said bucket in hauling relation to said anchor block, and winch means for hauling said dragline.

5. A dredge comprising a hull, an anchor block, means for raising and lowering said anchor block from said hull at approximately the center of buoyancy of said hull, a carriage mounted to travel along said hull toward and away from one end thereof, a dragline bucket, means for raising and lowering said bucket from said carriage, a dragline extending from said bucket in hauling relation to said anchor block, winch means for hauling said dragline, a second carriage counterweighted to compensate for the rst said carriage and its load and mounted to travel toward and away from the opposite end of said hull, and means to cause said carriages to travel in predetermined relation to each other toward and away from the center of buoyancy of said hull.

6. A dredge comprising a hull, an anchor block, means for hoisting said anchor block at approximately the center of buoyancy of said hull, a well extending through said hull at its center of buoyancy proportioned to receive said anchor block, a carriage mounted to travel along said hull toward and away from one end thereof, a dragline bucket, means for raising and lowering said bucket from said carriage, a dragline extending from said bucket in hauling relation to said anchor block, and winch means for hauling said dragline.

'7. A dredge comprising a hull, an anchor block, means for hoisting said anchor block at approximately the center of buoyancy of said hull, a well extending through said hull at its center of buoyancy proportioned to receive said anchor block, a carriage mounted to travel along said hull toward and away from one end thereof, a dragline bucket, means on said carriage for hoisting said bucket, a well extending through said hull and extending along said hull from one end thereof inward to'dene the travel of said bucket and being dimensioned to receive said bucket, a dragline extending from said bucket in hauling relation to said anchor block, and winch means for hauling said dragline.

8. A dredge comprising a hull, an anchor block. means for raising and lowering said anchor block from said hull at approximately the center of buoyancy of said hull, a carriage mounted to travel along said hull toward and away from one end thereof, a dragline bucket, means for raising and lowering said bucket from said carriage. a.

asomo! dragline extending .from said bucket .in hauling relation to said-anchor block, and winch .means for hauling said dragline, said Winch rmeans cornprising a drum journalled on said vanchor-block, a housing on said anchor block for winch mechanism, and means for excluding water from said housing.

A9. A dredge comprising a hull, an anchor block, means for raising and lowering 'said anchor block from said hull at approximately the center of buoyancy of said hull, a carriage mounted to travel along said hull toward and away from one end thereof, a dragline bucket, means for raising and lowering said bucket from said carriage, a

dragline extending from said bucket in hauling I relation to said anchor block, winch means for hauling said dragline, said winch means cornprising a drum journalled on said anchor block, Va housing on said anchor block for winch mech*- anism, and means for excluding water from said housing, said last-named means comprising a iiexible air pressure conduit extending between said housing and said hull and having counterbalanced take-up means to compensatefor raising and lowering of said anchor block.

10. A dredge comprising a hull, an anchor block, a dragline bucket, hauling means acting between said anchor block and bucket for operating the bucket, a well extending through said hull at its center of buoyancy proportioned to receive said anchor block, a second well extending through said hull and extending from one end thereof and inward to register with `the cutting travel of said bucket and of sufcient width to receive said bucket, a truss extending lengthwise of said hull above said Wells, hoisting means car- 38 Yriedby said truss for lift'ingzsai'd anchorpacarriagefmounted to 'travel on said trussv `alnn'gsz'ild lsecond Well, and hoisting-.means o'n-Sai'dlcarriage for lifting said bucket.

11. .A dredgefcomprising a hull, adrag bucket, cable means-for raising and lowering said bucket from said hull and arranged 'for hoisting 'and dumpingthe'bucket, an anchor` block, a drag line extending between 'said bucket Vand said anchor block, winch means for hauling `said drag line, cable means for hoisting said anchor block toward said hull, 'and hawser means extending between said hull andanchor block for adjusting said hull longitudinally and laterally relative to said anchor block.

v12. `A dredge comprising a hull, a dragline bucket, ymeans for raising rand lowering said bucket from said hull, an anchor block, ineans for 'hoisting said anchor block toward saidhulLdragline means extending between said bucket -and said anchor block, and winch means on vsaid anchor :block enacting Withsaid dragline means so as to haul Said bucket toward said anchor block, when said anchor block is 'resting `on `the river vbottom beneath said hull, `without transmitting strains to thehuil.

GEORGE B. MASSEY.

REFERENCES CITED The Vfollowing references are of record in the :le of this patent:

UNITED STATES PATENTS Number Name Date 1,723,115 Zickgraf Aug. 6,' vv1929 2,153,557 Grenier Apr. "11, '1939 

